Tunable conductivity at LaAlO3/SrxCa1-xTiO3 (0 <= x <= 1) heterointerfaces

Abstract

The two-dimensional electron gas formed at LaAlO3/SrTiO3 heterointerfaces exhibits a variety of interesting physical properties. Herein, we report on tunable conductivity at LaAlO3/SrxCa1-xTiO3 heterostructures. By changing the Sr content in the SrxCa1-xTiO3 (0 <= x <= 1) layers, the orthorhombicity of the films, which inevitably accompanies TiO6 octahedral distortions in the unit cells, could be varied. As a result, the interfacial conductivity can be tuned over 6 orders of magnitude. We suggest that the use of pseudosubstrates with chemical substitution or alloying is a promising route to finely tune conductivity at oxide heterointerfaces. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4773986]